Adjustable connecting arm

ABSTRACT

A connecting arm for transmitting motion from a windshield wiper motor to a windshield wiper arm is adjustable, lengthwise to permit accurate positioning of the windshield wiper arm in the parked position. The connecting arm includes a toothed surface meshing with an opposed toothed surface on an adjustable connecting arm end extension. The connecting arm end extension is secured to the end of the connecting arm with the opposing toothed surfaces in engagement. A releasable latching mechanism provides a compressive force between the connecting arm and connecting arm end extension to maintain the opposing toothed surfaces in meshing engagement when the arm extension is disposed in a suitable position. When the latching mechanism is released the connecting arm and the connecting arm end extension may be moved longitudinally relative to each other. The latching mechanism includes a bifurcated clip for securing a stud in a journal bearing at the end of the arm extension. A single latching operation retains the connecting arm in position in the linkage transmission and locks the adjustable end extension in proper position.

United States Patent 1 1 Deibel et al.

1451 July 17, 1973 ADJUSTABLE CONNECTING ARM- [75] lnventorsi Raymond A.Deibel, West Falls;

William C. Reister, Williamsville, both of NY.

[73] Assignee: Trico Products Corporation, Buffalo,

221 Filed: Mar. 22, 1972 21 Appl. No.1 236,850

56 I References Cited UNITED STATES PATENTS 11/1950 Anderson 287/65 R9/1952 Oishei l5/250.13

Primary ExaminerCharleS J. Myhre Assistant Examiner-F. D. ShoemakerAttorney-E. Herbert Liss [57] ABSTRACT A connecting arm for transmittingmotion from a windshield wiper motor to a windshield wiper arm isadjustable, lengthwise to permit accurate positioning of the windshieldwiper arm in the parked position. The connecting arm includes a toothedsurface meshing with an opposed toothed surface on an adjustableconnecting arm end extension. The connecting arm end extension issecured to the end of the connecting arm with the opposing toothedsurfaces in engagement. A releasable latching mechanism provides acompressive force between the connecting arm and connecting arm endextension to maintain the opposing toothed surfaces in meshingengagement when the arm extension is disposed in a suitable position.When the latching mechanism is released the connecting arm and theconnecting arm end extension may be moved longitudinally relative toeach other. The latching mechanism includes a bifurcated clip forsecuring a stud in a journal bearing at the end of the arm extension. Asingle latching operation retains the connecting arm in position in thelinkage transmission and locks the adjustable end extension in properposition.

7 Claims, 6 Drawing Figures PME NT ED Jun 1 I913 SHEET 2 OF 2 BACKGROUNDOF THE INVENTION The present invention relates to an adjustableconnecting arm for a windshield wiper transmission linkage assembly. Inwind-shield wiper transmissions a connecting arm extends between a crankarm fixed to the motor piston shaft and a slave arm or other linkageelement in the assembly. Current practice is to install the linkagetransmission assembly and then to mount the wiper arms so that they lieas close as possible to the desired park position. Wiper arms onpassenger vehicles include an internally knurled recess in a mountinghead which fits on an externally knurled cylindrical drive burr. Theangular displacement between teeth on the mounting head and drive burris such as to permit accurate adjustment to within about four degrees.Thus, the parked position of the wiper arm may vary from the desiredparking position by as much as four degrees. Variations in positioningmay also result from manufacturing tolerances in the transmissionsystem. The displace ment from the desired park position can becorrected by employing an adjustable length connecting arm and byvarying its length during installation.

SUMMARY OF THE INVENTION The unique and novel construction of theadjustable connecting arm assembly of this invention facilitates andexpedites installation and accurate positioning of the wiper arms. In asingle operation the connecting arm may be positively retained at itsproper adjusted length and secured to the adjacent linkage element. Alongitudinally adjustable connecting arm end extension is releasablylatched in position on the connecting arm. When released the connectingarm end extension is longitudinally movable relative to the connectingarm. The wiper arm may be mounted on the drive burr of the pivot shaftat the nearest possible position to the desired parking position becausewith the latch released the connecting arm assembly isadjustable inlength by application of a longitudinal force. The connecting armassemblywill thus assume the length necessary to maintain the wiper inthe desired parkposition. A rotatable latching lever is then moved tolatching position to fix the connecting arm end extension againstlongitudinal movement relative to the connecting arm. Concurrently thelatching lever secures a stud on an adjacent linkage element in thejournal bearingat the end of the connecting arm assembly for pivotalmovement. This dual purpose latch lever assembly serves to release theconnecting arm end extension to permit adjustment of the arm lengthduring installation. When the latch lever is rotated to closed position,the connecting arm end extension is secured in fixed position relativeto the connecting arm. A bifurcated spring lock engages acircumferential groove at the exposed end of a stud mounted on anadjacent linkage element which is journalled in the bearing assembly atthe end of the connecting arm end extension. With a single motionthewiper system can be latched in the desired operative position. Thisgreatly facilitates wiper system installation.

The principal object of the present invention is to provide a simple,economical, adjustable connecting arm assembly for a windshield wiperlinkage transmission which facilitates installation of the systemandproper positioning of the wiper arm.

Another object of the invention is to provide a connecting arm forwindshield wiper transmission linkage which is adjustable in lengthduring installation and which can be securely latched in the desiredoperative position and concurrently secured for .pivotal movement to anadjacent element in the transmission.

Other objects and advantages of the invention will be apparent from thefollowing detailed description taken in connection with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspectiveview of a motor vehicle incorporating the invention;

FIG. 2 is a perspective view of the connecting arm as- I DETAILEDDESCRIPTION OF THE INVENTION Referring to the drawings FIG. 1 shows afragment of a motor vehicle 10 having a windshield l2. Pivot shaftbearing housings 14 are suitably positioned at the cowl of the vehicle,and have pivot shafts (not shown) journaled therein. At the outer end ofthe pivot shafts there are mounted wiper arms 16 for rotation therewith.At the inner end of pivot shafts beneath the cowl, crank arms 18, 18'are secured. Slave arm 20 is connected at each end to one of the crankarms 18, 18'JA wiper motor and gear box assembly 22 having a crank arm24 secured to the output shaft is suitably mounted within the enginecompartment adjacent to the fire wall. A connecting arm assembly 26extends between the free end of the crank arm 24 and the free end of thecrank arm 18 at one of the pivot shafts. The connecting arm assembly 26is pivotally secured to the crank arms 18 and 24. The crank arms 18 and24, slave link 20, and the connecting arm 26 constitute a linkagetransmission assembly 28 for transmitting motion from the motor assembly22 to the wiper arm 16 and for converting the rotary output of the motorassembly 22 to oscillation of the wiper arms.

It can be seen from the FIG. 1 that when the position of the crank arm24 is fixed the positionof the wiper arms 16 can be changed by alteringthe length of the connecting arm assembly 26 but that when the length ofthe connecting arm assembly 26 is fixed and the position of the crankarm 24 is fixed there can be no movement of the wiper arms 16. Duringinstallation it is often necessary to make minor adjustments in theposition of the wiper arms to achieve a proper parking position againstthe lower molding of the windshield so that the drivers view is notobstructed when the wiper is parked. For this purpose the connecting armassembly 26 of this invention is made adjustable for purposes ofinstallation.

The connecting arm assembly 26 comprises main connecting arm 30,connecting arm end extension 32 and a latch lever assembly 34. Theconnecting arm 30 is slotted adjacent its end with the major axis of theslot 37 coincident with the longitudinal axis of the arm. It is serratedat the end preferably with coined teeth 36 on one surface. Theconnecting arm end extension 32 includes a bearing assembly 38 adjacentan end thereof which may be of any suitable type capable of accomodatingcanting of the arm, as for example, acompression mounted bearing asshown in U. S. Pat. No. 3,316,033 issued Apr. 25, 1967 by Peter C. Bilaand assigned to the assignee of the present invention. The arm endextension 32 is also toothed on a surface as at 40 so as to mesh withthe coined teeth 36 on the connecting arm 30. An opening 42 in the armend extension 32 is disposed in alignment with slot 37 of connecting arm30. A headed stud 44 is received through opening 42 and slot 37. Acontoured flat spring 46 having an opening 48 overlies the connectingarm 30 with the opening 48 in alignment with the slot 37. A clamping orlatching lever 50 overlies the flat spring 46 and has a polygonalopening 52 in alignment with opening 48, slot 37 and opening 42. Thestud 44 comprises a head 54 and a cylindrical shaft 58 corresponding insize to the opening 42. The shaft 58 at its free end 60 is formed tocorrespond in size and shape to the polygonal shaped opening 52 in latchlever 50. The shaft or post 58 of stud 44 extends through alignedopenings 42, slot 37, and opening 48. The polygonal end portion 60 ofthe shaft is-received in opening 52 and peened over thereby renderingthe shaft 58 movable with the latch lever 50. Other suitable means maybe employed to retain the stud. A pair of spaced apart projections 56 onthe head 54 of the stud 44 are aligned with recesses 62 on theconnecting arm end extension 32 in the open or released position of thelatch lever 50; when the latch lever is in the latched position theprojections 56 ride out of the recesses 62 compressing the assembly andcausing the opposed teeth 36 and 40 to engage against the bias of flatspring 46. A lug 64 struck up from flat spring 46 engages with anaperture 66 in the latch lever 50 to render the flat spring 46 movablewith the latch plate or lever 50. Secured to one end of the latch lever50 is latch element comprising a reversely bent bifurcated spring latch68 which overlies the bearing 38 on the arm end extension 32 when thelatch assembly is in a latched condition. The bifurcations engage acircumferential recess 69 adjacent the end of a stud 70. Stud 70 issecured to the motor crank arm 24 and in assembled condition isjournaled in bearing assembly 38. The latch lever 50, the shaft 58 ofstud 44 and the flat spring 46 may be rotated on an axis extendingthrough the openings 42, 48 and slot 37; they are operatively securedtogether for conjoint rotation.

When the latch 50 is rotated so that its longitudinal axis is inalignment with the longitudinal axis of the connecting arm 30 andconnecting arm extension 32, the flat spring 46 is under compression.The projections 56 ride out of the recesses 62 to effect a compressiveforce, acting on the connecting arm 30 and arm end extension 32, therebycausing the teeth 36 and 40 to mesh in locking engagement. Thebifurcated latch spring 68 engages the circumferential groove 69 in thestud 70 thereby simultaneously rigidly securing the arm end extension 32to the connecting arm 30 and also locking the connecting arm assembly inposition. Rotation of the latch lever 50 to a position where itslongitudinal axis lies transversally to the longitudinal axis of theconnecting arm 30 causes the projections 56 to drop into the recesses 62thereby relieving the compressive force between the connecting arm 30and the connecting arm end extension 32. This effects a disengagement ofthe opposing teeth 36 and 40 permitting longitudinal movement of theconnecting arm 30 relative to the arm extension 32. This is possiblebecause the elongated slot 37 is longitudinally movable on the stud 44.To prevent rotational movement of the arm end extension 32 relative tothe connecting arm 30, the connecting arm 30 is flanged on each side asat 74. The inner end of the arm extension 32 remote from a bearing 38 isbent up as at 76 to lie between the flanges 74.

OPERATION The operation of the invention should now be apparent. Withthe motor assembly 22, the linkage transmission 28 and the wiper arms 16having wiper blades 16 secured thereto all mounted on the vehicle, latch50 is placed in the released position with its longitudinal axis lyingtransversely to the longitudinal axis of the connecting arm 30 as seenin FIG. 2. With the motor assembly 22 and its crank arm 24 set in parkedposition, the wiper arms are mounted on their respective pivot shafts asclose to a parked position as is possible as shown in the solid lineposition of FIG. 1. The arms may then be manually moved to the idealparked position against the lower molding of the windshield as shown inthe dotted line position of FIG. 1. In the example illustrated theconnecting arm assembly 26 is subjected to a compressive force along thelongitudinal axis causing the arm end extension to move from theposition shown in FIG. 2 to the position shown in FIG. 3. It will ofcourse be understood that in certain arrangements a tension force may beapplied causing the connecting arm to expand longitudinally. When thearms 16 are set in the desired parked position the latch is moved to itslocked position shown in FIG. 3, thereby applying a compressive force onconnecting arm 30 and the arm end extension 32 causing the teeth 36 and40 to mesh and lock. Thus the connecting arm assembly 26 is securelyretained at the length necessary to maintain the wiper arms 16 againstthe lower molding of the windshield when the wiper is in parkedposition. Concurrently the bifurcations of spring latch 68 engage groove69 of stud to secure the connecting arm assembly 26 to the crank arm 24for pivotal movement about the axis of stud 70.

Another preferred embodiment of the invention is illustrated in FIGS. 5and 6. In this embodiment connecting arm end extension 32' overliesconnecting arm 30. Connecting arm 30' is serrated with coined teeth 36'on one surface and connecting arm extension 32' is serrated with coinedteeth 40' on its surface in opposition to the teeth 36. The connectingarm is slotted at 42', the slot 42- having its longitudinal axiscoincident with the longitudinal axis of the connecting arm 30. The freeor outer end of the arm end extension 32' includes a compression mountedbearing assembly 38 which may be identical to the bearing assembly 38 onthe arm extension 32 as shown in the FIG. 2 embodiment. Overlying thearm extension 32 is a latching plate 50' having a bifurcated springlatch 68 identical with the spring latch 68 in the FIG. 2 embodiment.Openings 48' and 52' are provided in the arm extension 32' and the latchplate 50 respectively. The opening 48' and 52' are in alignment with theslot 42 in the connecting arm 30. Circumscribing the openings 48' and 52and opposite to each other are cooperating cam surfaces 49 and 53',respectively, on opposed faces which engage each other. A headed stud44' is received through the aligned openings 52', and 48' and slot 42'.The latch plate 50' is rotatable on an axis through the slot 42 andaligned openings 48' and 52. A retaining and spacing ring 60 may beprovided to take up the manufacturing tolerances between parts and toretain the latching plate 50 and arm extension 32' on the connecting arm30'. The parts may be assembled in overlying relationship as described.The ring 60' may be disposed on the exposed free end of the stud 44'which may have a circumferential groove 61' formed therein. The ring 60'may be crimped as at 63 to engage the groove 61' for retaining the partsin assembled condition.

A pair of down-turned ears 74 is provided on the arm end extension 32which receive the connecting arm 30' in nestled relationship therebypreventing rotational movement between the connecting arm 30 and arm endextension 32'. A lug 76 is provided on the latch plate 50 to limitrotational movement of the latch plate. The cammed surfaces 49' and 53'circumscribing the openings 48 and 52 are so formed as to apply acompressive force between arm extension 32' and the connecting arm 30'when the longitudinal axis of the latch plate 50' is coincident with thelongitudinal axis of the arm end extension 32'. This is the latchedcondition and causes the teeth 40' and 36 to mesh in locked engagement.When the latch plate 50 is rotated to the position shown in FIG. 5 withits axis transverse to the longitudinal axis of the connecting arm 30'and arm extension 32 the compressive force acting between the connectingarm 30' and the arm extension 32' is relieved by the cooperating camsurfaces 49' and 53' or ramps circumscribing the openings 52' and 48.This permits longitudinal movement of arm end extension 32 relative tothe connecting arm 30' until the latch is again rotated to the lockedcondition.

The operation and function of the FIG. 5 embodiment is similar to theoperation and function of the embodiment shown in FIG. 2. Thetransmission and motor are installed in the vehicle; the motor is set inparked position; the arms are mounted on their respective pivot shaftsin the solid line position of FIG. 1 as close as possible to the finalpark position; the latch plate 50' is set in its unlocked positionpermitting longitudinal movement of the arm extension 32 relative to theconnecting arm 30'. Then the wiper arms 16 are manually moved to thedotted line position against the lower molding of the windshield. Thismovement is permitted due to the freedom of the connecting arm assembly26' to extend or collapse longitudinally as the case may require. Whenthe wiper arms are properly positioned the latch plate 50 is rotated tolocked condition. The spring latch 68 engages groove 69 in stud 70.

An adjustable crank arm assembly for a windshield wiper linkagetransmision has been provided which permits accurate positioning of thewiper arms during installation and which positively maintains the armsin such adjusted position. The movable crank arm of the inventionsimplifies installation obviating the need for auxiliary tools foradjustment and also serves to retain the connecting arm and the adjacentmotor crank arm 24 in assembled operative position with the connectingstud 70 journaled in the bearing assembly 38 for pivotal movement.

Although certain sp'ecific embodiments of this invention have been shownand described for the purpose of illustration, it will be apparent thatin accordance with its broadest aspects various modifications and otherembodiments are possible within the scope of the invention. It is to beunderstood therefore that the invention is not limited to the specificarrangement shown but in its broadest aspects it includes all equivalentembodiments and modifications which come within the scope of theinvention.

What is claimed is:

1. In a linkage transmission assembly for a motor vehicle windshieldwiper system; an adjustable connecting arm assembly comprising aconnecting arm, a connecting arm end extension secured to saidconnecting arm in overlapping relationship adjacent an end thereof forlongitudinal sliding movement relative to said connecting arm,cooperating engaging means on opposed faces of said arm end extensionand said connecting arm in the overlapping area for preventing relativelongitudinal movement, a releasable latch lever assembly operativelysecured at said overlapping area having camming means acting on saidconnecting arm assembly to apply a compressive force between said armend extension and said connecting arm when said latching lever assemblyis moved to a first position to thereby cause engagement of saidcooperating engaging means and to effect release of said compressiveforce to permit disengagement of said cooperating engaging means whensaid latch lever assembly is moved to a second position whereby said armextension and said connecting arm can move longitudinally relative toeach other.

2. An adjustable connecting arm assembly according to claim 1 whereinsaid latching lever assembly includes a latch lever having a bifurcatedspring latch at an end thereof for engagement with a stud on an adjacentlinkage element when in latched position.

3. An adjustable connecting arm assembly according to claim 1 whereinsaid latching lever assembly comprises a latch lever disposed in a planeparallel to said connecting arm assembly and a headed stud securedthereto intermediate the ends of said lever, the longitudinal axis ofsaid headed stud forming the axis of rotation for said lever, said armend extension and the end of said connecting arm lying intermediate thehead of said stud and said lever.

4. An adjustable connecting arm assembly according to claim 3 whereinsaid latch lever assembly is attached to said stud for rotationtherewith.

5. An adjustable connecting arm assembly according to claim 4 whereinsaid camming means comprises projections on the head of said studextending toward a surface of said connecting arm end extension, saidconnecting arm end extension having recesses on said surface receivingsaid projections when said lever is in unlatched position to therebyrelieve the compressive force acting between said connecting arm andsaid arm end extension.

6. An adjustable connecting arm assembly according to claim 3 whereinsaid camming means comprises a cam surface on said latch lever disposedadjacent a cooperating cam surface on said arm end extension wherebysaid cam surfaces engage to apply a compressive force between said armend extension and said connecting arm when said latch lever is inlatching position and said cam surfaces disengage to relieve the stud ofan adjacent linkage element and wherein said latch lever includes alatch element for engaging the stud of the adjacent element to latch itin assembled position when said latch lever is in latched position.

1. In a linkage transmission assembly for a motor vehicle windshieldwiper system; an adjustable connecting arm assembly comprising aconnecting arm, a connecting arm end extension secured to saidconnecting arm in overlapping reLationship adjacent an end thereof forlongitudinal sliding movement relative to said connecting arm,cooperating engaging means on opposed faces of said arm end extensionand said connecting arm in the overlapping area for preventing relativelongitudinal movement, a releasable latch lever assembly operativelysecured at said overlapping area having camming means acting on saidconnecting arm assembly to apply a compressive force between said armend extension and said connecting arm when said latching lever assemblyis moved to a first position to thereby cause engagement of saidcooperating engaging means and to effect release of said compressiveforce to permit disengagement of said cooperating engaging means whensaid latch lever assembly is moved to a second position whereby said armextension and said connecting arm can move longitudinally relative toeach other.
 2. An adjustable connecting arm assembly according to claim1 wherein said latching lever assembly includes a latch lever having abifurcated spring latch at an end thereof for engagement with a stud onan adjacent linkage element when in latched position.
 3. An adjustableconnecting arm assembly according to claim 1 wherein said latching leverassembly comprises a latch lever disposed in a plane parallel to saidconnecting arm assembly and a headed stud secured thereto intermediatethe ends of said lever, the longitudinal axis of said headed studforming the axis of rotation for said lever, said arm end extension andthe end of said connecting arm lying intermediate the head of said studand said lever.
 4. An adjustable connecting arm assembly according toclaim 3 wherein said latch lever assembly is attached to said stud forrotation therewith.
 5. An adjustable connecting arm assembly accordingto claim 4 wherein said camming means comprises projections on the headof said stud extending toward a surface of said connecting arm endextension, said connecting arm end extension having recesses on saidsurface receiving said projections when said lever is in unlatchedposition to thereby relieve the compressive force acting between saidconnecting arm and said arm end extension.
 6. An adjustable connectingarm assembly according to claim 3 wherein said camming means comprises acam surface on said latch lever disposed adjacent a cooperating camsurface on said arm end extension whereby said cam surfaces engage toapply a compressive force between said arm end extension and saidconnecting arm when said latch lever is in latching position and saidcam surfaces disengage to relieve the compressive force when said latchlever is in unlatched position.
 7. An adjustable connecting arm assemblyaccording to claim 6 wherein said arm end extension includes a journalbearing adjacent its free end for receiving a stud of an adjacentlinkage element and wherein said latch lever includes a latch elementfor engaging the stud of the adjacent element to latch it in assembledposition when said latch lever is in latched position.